The sun produces energy by fusing hydrogen atoms into atoms in its core.
a. carbon
c. iron
b. helium
d. oxygen

(b) Helium. It is the nuclear fusion of four hydrogen atoms with a helium atom that the core of the Sun's hydrogen is converted into Helium. This produces the huge amount of energy which makes the sun burn. It is due to the difference in the binding energy of more nuclei with one that produces the large amount of energy.Hope this helps. Let me know if you need additional help!